The former Strikeforce champion, who infamously cost himself a title shot with Georges St-Pierre when he skipped pre-event media commitments, instead took out his frustrations on B.J. Penn and battered the former UFC champ into the night’s second career retirement.

The fight headlined the pay-per-view main card of Saturday’s UFC 137 event, which took place Saturday at the Mandalay Bay Events Center in Las Vegas.

Both fighters showed impressive striking accuracy in the first round, one in which Penn took Diaz’s back but couldn’t capitalize once on the mat. But on the feet, he matched Diaz’s punches and landed the type of accurate blows the former Strikeforce champ has rarely dealt with in recent fights.

In the second, Penn again was willing to stand flatfooted in the pocket, and especially in the clinch, he did damage with punches. But Diaz returned fire with some body shots and knees to the head while Penn was backed against the cage. The exchanges built Diaz’s confidence, and with his first true taste of blood, he teed off with more frequency and dug into Penn’s ribs with body shots. Subsequent combinations put Penn in survival mode, and the former two-division champ took heavy damage in surviving the final minutes of what proved to be a disastrous round for him.

Despite the lopsided second round, Penn was willing to play Diaz’s game in the third. He got sucked into the streetfight and had his moments, but Diaz’s stellar conditioning and avalanche of punches simply proved too much to overcome. The fighters closed out the round by dishing out a ridiculous amount of damaging punches, but Penn, who was badly bloodied and bruised in the fight, couldn’t get the finish he needed for the victory.

In the end, the judges scored it 29-28, 29-27 and 29-28 in Diaz’s favor.

After the fight, a seemingly dejected Penn said his illustrious career is over.

“Hats off to Nick Diaz,” he said to interviewer Joe Rogan. “He’s the man. Joe, this is probably the last
time you see me in here. I want to perform at the top level. … I’ve
got a daughter. I’ve got another daughter on the way. I don’t want to go
home looking like this.”

And with that, Penn left the cage.

Diaz, meanwhile, was already looking ahead to his next challenge, namely St-Pierre. When Diaz no-showed a pair of press conference, Diaz lost his title fight with St-Pierre, who ultimately scratched from a bout with Carlos Condit due to a knee injury.

With the triumphant return to the octagon, Diaz (26-7 MMA, 7-4 UFC) picks up his 11th consecutive victory.

Penn (16-8-2 MMA, 12-7-2 UFC), one of the biggest names in MMA history, apparently closes out his career with a 1-3-1 run in his final five fights.

Kongo tops Mitrione via decision

Perhaps gatekeeper is the role Cheick Kongo was meant to fill.

In the night’s co-headliner, the veteran UFC heavyweight delivered fast-rising heavyweight Matt Mitrione his first career loss, though he made few fans in the process.

The first round of the heavily hyped fight proved a dud, and boos rained down as both proved overly cautious and hesitant to throw anything but single punches.

In the second, the fighters traded and landed early leg kicks, and the punches then began landing with more frequency. However, anytime Kongo would build momentum, Mitrione returned fire and slowed the attack. A late uppercut and a few lunging shots likely earned the NFL vet the round over Kongo.

Kongo, though, came out strong in the third. He landed a couple big punches and then picked up and slammed Mitrione to the mat. Mitrione eventually got back to his feet, but his left eye was badly damaged, and Kongo soon wrapped the hips and took him back down, where he closed out the round with some occasional ground and pound.

It wasn’t pretty, but it was enough to earn Kongo the victory via 30-27, 30-28 and 29-28 scores.

“I wasn’t sure how to react to Mitrione’s movements in the beginning,” he said. “I was happy with my performance, especially my striking. I wanted to make him work. My game plan was to wait and see what he did.”

Kongo (17-6-2 MMA, 10-4-1 UFC), who was fresh off a miracle comeback win over Pat Barry, is now 4-0-1 over his past five fights. Mitrione (5-1 MMA, 5-1 UFC) suffers the first loss of his two-year career.

Nelson retires “Cro Cop,” picks up TKO victory

Mirko “Cro Cop” Filipovic wanted to conclude his career with a victory, but a slimmed-down Roy Nelson sent the heavyweight legend into retirement on the receiving end of a TKO loss.

In what Filipovic said was his “farewell fight,” the Croatian had his moments and had his opponent in trouble on multiple occasions, but Nelson’s aggression and dominant ground work led him to a third-round stoppage.

Each fighter landed heavy blows in the first two rounds. Nelson landed some lunging shots in the first, and after slipping on a blow in the second, he found himself pounced upon by Filipovic, who unloaded a dizzying barrage of punches to the head and gut as Nelson helplessly tried to cover up against the cage. But Nelson scored a takedown, landed in side control, moved into the crucifix position and closed out the round with dozens of unobstructed blows.

Filipovic quickly wanted to turn the tides in the third round and came out swinging. However, Nelson, who pushed the pace and often chased during the fight, capitalized on a slip, followed Filipovic to the mat, took back mount, and unloaded heavy punches to force the TKO stoppage.

The end came at 1:30 mark of the final frame.

After the bout, Filipovic – the former PRIDE great who never captured the same magic in the UFC – called it a wrap on his 10-year MMA career.

“I wanted to say goodbye with a victory, but Roy was just the better fighter tonight,” he said. “The UFC has been so good to me over the years, and it is hard to leave this company and this sport. Even though I didn’t do as well in the UFC as the rest of my career, I feel like I did everything that I could to have an overall successful career.”

Nelson, who jokingly called out the winner of next month’s Cain Velasquez vs. Junior Dos Santos title fight (“because I’m getting too old for this [expletive]”), was pleased to topple MMA royalty.

“It was awesome to fight with a legend,” he said. “It’s good just to be back in the [win] column. ‘Cro Cop’ can still tear it up. My game plan was to strike and mix it up so you see a little bit of everything.”

Nelson (16-6 MMA, 3-2 UFC), who had lost back-to-back fights, surely saved his UFC career with the win. Filipovic (27-10-2 MMA, 4-6 UFC) concludes his career with three straight defeats.

Jorgensen wins ugly over Curran

Scott Jorgensen didn’t so much win as he forced Jeff Curran to lose.

With his proven wrestling base and submission defense, Jorgensen shut down the returning UFC bantamweight’s offense and scored a dominant (though far from flashy) unanimous-decision victory.

After an early takedown, Jorgensen shut down Curran in the first round with a smothering top game. The second round was much of the same, and Jorgensen quickly freed himself of any potential troublesome positions during the exchanges.

Curran got the distance he needed in the third and landed some heavy punches and effective body kicks, but he couldn’t put together any sustained attacks. He did manage to fend off frequent takedown attempts, but despite a valiant effort, he couldn’t get the finish he desperately needed by fight’s end.

In the end, the judges awarded Jorgensen the unanimous-decision win via 29-28, 29-28 and 30-27 scores.

“I would have loved a more exciting fight, but that’s the way it goes sometimes,” he said. “I’m happy to be back on a winning streak. I wasn’t as explosive or exciting as usual, but I fought the fight I wanted to.”

Jorgensen (13-4 MMA, 2-0 UFC) moves to 7-1 over his past eight fights, and the lone loss came in a title fight with champ Dominick Cruz. Curran (33-14-1 MMA, 0-2 UFC), a WEC vet who fought in the UFC for the first time since 2004, suffers just his second loss in six fights.

Roop proves game, but Hioki wins UFC debut

Highly touted UFC featherweight newcomer Hatsu Hioki has his hands full, but he ultimately made a successful debut and scored a close split-decision victory over scrappy George Roop.

Roop scored early with lunging punches and kicks from various angles. But in the first two rounds, Hioki used stifling clinch work, slick takedowns and a controlling top game to keep a slight edge. His biggest gaffe came when Roop tagged him with a flush upkick to the face at the end of the second round, which prompted the former Sengoku champ to back away and allow his opponent to stand.

A determined Roop instantly scored a tackle-takedown as the third round began, but Hioki quickly was back up. He then kept the action close and fought from the clinch before the ref stepped in. On the restart, Roop scored a stutter-step takedown and worked from the top, but Hioki tied him up from below and avoided any substantial damage.

The judges were split, and Hioki squeaked by with the win via 29-28, 28-29 and 29-28 scores.

“My game plan was to take him down, but George kept great distance,” he said. “It feels great to get my first UFC victory, but it was tougher than I expected.”

Hioki (25-4-2 MMA, 1-0 UFC) now has won five straight fights, and he’s 13-1-1 over his past 15 fights. Roop (12-8-1 MMA, 2-4 UFC), who’s been fed a steady diet of top-10 talent, has gone nearly four years without back-to-back wins.

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